[fbov]

I've owned a 2020 Escape Hybrid for a few days now and it is apparent that certain techniques and habits lead to significantly better utilization of the battery and, subsequently, much better MPG. ...

Good idea. Comments based on years of C-Max and about 1800 miles in the 2020. I'm sure Paul Jones will chime in, as he's the C-Max Master.

First habit is to use EV coach whenever you're using EV. The feedback will train you to sustain EV and use less fuel.

NORMAL Mode (default) vs. ECO Mode

• Agree that this should be "sticky," but not sure I want all 5 options to stick. Some folks will get stuck on SPORT (0% EV) or SAND (100% AWD).
• Most noticeable difference in ECO mode is to move the "zero point" between EV and Regen where the car is coasting. NORMAL mode coasting requires a little throttle. In ECO, it needs a lot more throttle. At speed, off-throttle in Eco mode can get me 17kW of regen... out of a max of 35kW available (highest number I've seen).
• Biggest advantage is that ECO mode makes Intelligent Cruise with Stop-and-Go functional.
  There's no lurch pulling into the passing lane when following slower traffic.

Acceleration

• You describe what's called "chasing blue" on the C-Max forum. As you surmised, the blue outline is "EV Available." You can EV until the outline is full, without starting the internal combustion engine (ICE), but the outline shrinks as you deplete the HV battery. (Size of outline is the only HVB state of charge indicator I can find.)
• When HVB SOC is high, EV contributes to ICE torque - hybrid mode. That leads to an acceleration rule.
  Acceleration rule #1: To maximize HVB charging from the ICE, stay out of hybrid mode; keep EV at 0.
  It's just common sense; if you want a battery to have high charge, don't discharge it!
• I've also found that very low EV (1-2 kW) will not start the ICE for a long time. You pay the price in a highly depleted HVB that needs ICE to move from stopped, but I got to the stop without ICE.

Deceleration

• Max I've seen is 35kW regen, and that at speed. The value drops as the car slows. Brake Coach is like school grading; anything over 93% gets an "A." No benefit to perfection.

Efficient Speeds

• There are none when you realize that driving under EV uses no fuel at all... you can coast a long time with a little EV assist. Going slower can always improve MPG, but it's also unrealistic at some point.
• The problem is that faster requires more power. Based on EPA fuel economy testing, here are the Road Load Horsepower curves for C-Max, and 2020 Escape FWD and AWD (150 lb. heavier).

(Note that 1 HP = 0.746 kW, so 20 HP is about 15 kW)

The most obvious feature is the strong upward trend, roughly the square law: 30 MPH requires 1/4 the power of 60 MPH, and from 60 MPH, you need 50% more to hold 70 and twice 60's power to make 80 MPH.

Next, I look at the relative curves; AWD > FWD at all speeds, and the C-Max curve crosses the Escape pair in the only possible way: less power required at high speed due to a smaller cross-sectional area and less drag. Ford's engineers are to be commended for reducing non-aerodynamic losses sufficiently to best C-Max power needs at 30-50 MPH with a larger engine.

General

• Yes, the blue outline is the closest we have to an HVB gauge. I use the letters of the word ELECTRIC to calibrate. I can get 22kW if it's past "i" but 19 kW normally starts ICE. What's impressive is how fast it recovers to the "t" to "r" range with a short ICE run.
• Just as there are "acceleration rules" there are operational rules. Drop throttle is critical to achieving high mileage because you can't play the Hybrid Game otherwise. C-Max cruise control did this beautifully.
  Drop Throttle: reduce throttle below regen threshold then increase between the regen and ICE threshold to enter EV mode.
  Now, play the game: ICE uphill, EV down. You'll find where the transitions are that keep HVB from running dry at the wrong time (like the start of a long, gentle downslope). If you commute, you'll learn every rise in the road.
• I agree about the dash being lug-in centered; the owners' manual makes me jealous. And this is not a "mild" hybrid. As you learn to drive it (took me a year), you'll be in EV a lot more.

Additional Thoughts
This is a very nice car.
Handling is impressive, yet ride is very comfortable. These are not your grandfather's Ecopias.
Seats could use side support, but they're fine over long distances (650 miles/day).
Driver assistance features rarely get in the way. Corrections feel like a crosswind.
The touchscreen display is fine, but the dash is poor; too much glitz and animation, too little info communicated.
EV Assist is your friend.
And, Ford, how about adding an EV fuel gauge to EV Assist? Please????

Stay well,
Frank

 

[fbov]

I spent some time the last day or two rolling with intelligent cruise + stop-n-go. Did this is both ECO and NORMAL drive modes. I generally noted that this mode does about as well as I am able to do by doing the "hybrid game" thing. ..

Please let me clarify that I was speaking ONLY what happens when traffic has slowed you down, and the system thinks your path is clear and you can resume the set speed.
NORMAL floors it, ECO speeds up gently.

I was not speaking in regard to long term operation of intelligent cruise, just the absence of show-stoppingly bad behavior.

Stay well,
Frank

 

[fbov]

...I find posting trip data or instantaneous mpg data not very helpful for comparison purposes. ...

That's very true. For comparison purposes, you'd like round trip data, with nearly equal legs. My old commute to work was perfect.

In retirement, I have lots of 35/65 trips. The average of 35 and 65 is 50, but the right answer is (total miles)/(total gallons) = 45.5 MPG.

Stay well,
Frank

 

[fbov]

As someone who bought a C-Max grill cover from Paul, I'd like to point out that internal shutters can have substantial benefits which are nonetheless smaller than the benefits of a smooth front end with minimal air infiltration. Paul tested it, so his MPG improvement claim has data behind it. In the Northeast US, I never had a cooling issue, and I always had water temperature displayed in My View.

Take a close look at Paul's car... the grill block is just the start.

• front grill blocks, upper and lower.
• wheel disc covers
• rear wheel fairing
• (Paul, you still using vortex generators?)

For what it's worth, Saturday we got a 70F day, and I got to drive my old commuter route, round trip, for take-out Mexican. 56 going, 64 MPG coming back on the warm start. My C-Max ran in a similar range at that temperature, over that route, with increased tire pressures and grill blocks.. The Escape is 100% stock, save for 91E0; not even tire pressures (which are up a little with warmer weather... remember, these are P-metric, so max. is 41 psi.)

Stay well,
Frank

 

[fbov]

Hey, Paul! You should remind folks that you don't own an Escape Hybrid.

 

[fbov]

... the advice is to AVOID hybrid mode. That is, if I notice I'm in hybrid mode, accelerate so that I'm in ICE-only mode ...

There is no ICE-only "mode", per se, just EV (ICE off) and Hybrid (ICE on). In Hybrid mode, reducing throttle will bring EV power to 0, so you are not depleting the HVB. This is your ICE-only "mode."

The use-case I can think of is when going up a not-too-steep hill. So, instead of trying to stay in hybrid mode to allow the car to use less ICE, the suggestion is to go up the hill in ICE-only mode and then once I've crested the hill, go into EV mode.

Exactly right. I put the attached together for C-Max, but the Escape is very similar.

Burn fuel (chemical energy) at high efficiency. The car will apportion the resulting energy to accelerate the car (kinetic energy) or charge the HVB (electrical energy). As ICE runs to move the car, store energy in both the HVB and in altitude (potential energy). Then tap those stores to maintain speed in EV mode, with ICE off. Use as little HVB charge as possible by taking advantage of downslopes as you suggest. Charge gently uphill, EV down, then repeat on the next hill. You'll discover tiny hills you never noticed, but which change the car's speed. Learning those is grad school.

advice here is to use EV Coach when one is new to the vehicle. Why not just keep an eye on the right hand part of the dash display ...

Because you need a "fuel gauge" for the EV side. EV Coach shows the ICE-on threshold as an outline around the EV bar. The length of the outline is determined by HVB SOC. As you EV, the threshold starts to drop; the outline shrinks. That feedback allows you to adjust throttle to reduce EV demand before ICE comes on, as driving conditions require.

(I, too, have noticed that I can drive for a long time in EV-only at 1-2KwH on level ground)

Indeed. And EV coach tells you when to back off to that level.

Absent hills, or in addition to them, I use speed. Gently speed up using ICE, then EV using a little less throttle than required to maintain speed. Repeat. This is classic "pulse and glide" hypermiling technique and the car loves it.

I also find I get a lot more charging at 10kW ICE power up to about 20kW, while 30kW quickly gets into hybrid mode as SOC increases. That means a longer, gentler ICE run increases HVB SOC. That's very useful just before a long downhill.

TLAs - three letter acronyms.
HVB - high voltage battery. SOC - state of charge. ICE - internal combustion engine.
And MJ - megajoule, from the chart, is an alternate unit of energy, equal to 0.27 kWh... not sure why I didn't use kWh!

Stay well,
Frank

 

[fbov]

...The net effect of this is that one will not be maintaining a steady speed ... (hence the term "pulse & glide"...). Why is this more efficient than gently speeding up using ICE and then maintaining speed with EV until the SOC is low enough that the ICE kicks back on? ...

Very true. Combining a little coast-down with EV is very effective in preserving HVB SOC. As you've found with the 3kW trick, the less EV you use, the longer your HVB energy lasts. As the energy flow diagram shows, your only EV reduction options are to EV downhill, the gravity assist, or sacrifice some speed. Terrain is set by the road, speed is set by the driver. Do what you can do.

On the "pulse" side, high load at low RPM allows the ICE to work in an efficient operating region. Engine efficiency is measured as fuel mass per kWh, known as "Brake-specific Fuel Consumption" (BSFC). Here's a BSFC chart for a 2010 Prius engines (3rd gen.?). The key takeaway is that this engine needs no more than 220 gm. of fuel to produce 80-120 Nm of torque at 1500-3000 RPM. High load at low RPM gives greatest efficiency.

Secondly, more for curiosity than anything else, how did you determine that one gets more charging between 10-20kW ICE power?

Observation and experience. I wish I could find my ELM327 OBDII tap as ForeSCAN will tell you all this. It's based on listening to the engine, watching how fast the EV outline grows, and noting the threshold for Hybrid mode when running ICE-only. I've seen Hybrid mode at 20kW throttle, and I've pulled 40kW in ICE-only mode. The wide range of behavior correlates with HVB SOC. When the threshold is 20kW, the EV outline is out to "t" in "Electric" and almost nothing when the threshold is 40kW.

Listening tells me engine speed doesn't rise until about 10kW, setting a lower limit. The upper limit is extrapolated from the ICE-only threshold. The behavior is based on how long I need to run ICE on known routes where I have an established set of "burn" and "EV" transition spots. Drive a route 5 times a day and you get to know how long to charge here in order to make it there in EV. I've also found that reducing throttle cresting a hill will give me a little more energy through the trough.

... I might as well see if I can learn to do better (without driving my wife bananas when she's riding shotgun...)

Bananas are unavoidable. The C-MAX changed my personality, upped patience and tolerance for the slowpokes. It took the wife a few years but eventually, she got a hybrid too (Sonata). You guys are way ahead of us.

Stay well,
Frank

 

[fbov]

... accelerate from a stop using ICE, to maximize HVB SOC for later use.

I don't think we discussed this, because the lesson from C-Max is the opposite; get rolling on EV, then use ICE to come up to speed. We called it "chasing blue." At rest, the EV available outline is small. As you speed up, the outline grows. The "game" is to press the throttle gently enough that the solid bar (throttle) remains inside the expanding outline (available). C-Max was hard to ge past 10 mph, Escape gets to 20 mph easily before cutting over to hybrid.

The reason is in the kinetic energy equation, KE=1/2mv^2. Getting to 20 mph uses 1/4 of the energy needed to hit 40 mph, the kind of EV/ICE energy ratio you want. It's a chance to use a small amount of EV, followed by ICE charging. It's a small thing, but a real benefit accrues due to frequent use, literally every time you stop. Well... not every time. You do need a healthy SOC; don't expect it if you've run the battery down.

... followed by ICE acceleration at "2 bars." ... perhaps the functional equivalent of "2 bars" is "between 10kW and 20kW"?...

In C-Max, "2 bars" was the ICE-only threshold. Greater acceleration brought on Hybrid mode unless the HVB was empty. I'd say it's more like 30-35 kW in Escape.

The initial "how-to" for C-Max said to accelerate at 2 bars so you'd get up to speed and turn ICE off sooner, while still charging. I found I was running out of EV too soon. I started using more like 1.5 bars. It took longer to come up to speed, but I ran at lower RPM so a lower fuel usage rate. I had a 15 mile, 30 mph commute that provided a place to test. I found the added fuel used in the longer, lower ICE burn bought a much higher %EV and significantly higher mileage.

This taught me to look for changes in SOC based on how hard I accelerate. Escape is much more aggressive charging a low HVB, based on EV Available outline recovery. Love the liquid-cooled HVB!

Quite well done

Paul Jones is a top C-Max hypermiler, with the only 900 mile tank to my knowledge. His car is quite unique, but his modifications and driving techniques are backed up by consistent results. Curious to see what he does to the Escape.

Stay well,
Frank, who misses C-Max's My View tachometer display.

 

[fbov]

You're getting wrapped up in the details; drive a little and see what works for you.
Frank

 

[fbov]

1. Yes.
2. HVB charging at low SOC is the biggest improvement from C-Max, IMHO. I suspect liquid cooling can handle the greater thermal load from more aggressive charging. I avoid terms like "SOC rectangle" in favor of "EV-Available" because you only need partial charge for EV Available to max out at 20kW. I judge SOC by how long EV lasts before the outline shrinks, at varying EV throttle demands.
3. You're riding an electric motor torque curve, which are all flat at low RPM due to current limitations. Once you start moving, the EV Available bar inflates as current demands fall. I try to use the same gentle throttle application, regardless SOC.
   Sometimes I succeed.
   
4. The hybrid mode threshold is very SOC dependent, regardless the throttle. I've seen hybrid mode at 20kW after a long downhill, or at 40kW after a long EV stretch. How much throttle you need to make it up the hill is a separate question. If SOC is high, hybrid mode is hard to avoid.
5. I put auto-hold issues in the low SOC box. I agree it is noticeable.
6. 😁
   
   ICE - internal combustion engine
   SOC - state of charge
   HVB - high voltage battery

 

[fbov]

So, if I understand you correctly, what you are saying is that because the torque requirements...

Replace "torque" with "current" and yes, to first order. I'm not privy to engineering details, but physics still works.

It helps to get an idea how much current we're talking about. Ohm's Law gives you the basics, V=IR and P=IV, power = current x voltage. We have a 216v nominal HVB, so 21.6kW of EV requires 100A. My house has a 150A/240V service. You can see where people get the idea of using their hybrid car as a backup generator. The magic is in the AC-DC-AC conversion because motor speed is controlled by changing the AC frequency, while energy is stored in a DC battery. That's where all Toyota's intellectual property lives; the power-split device is c. 1972.

Are you familiar with the Weber State videos? He disassembles hybrid drivetrains, electronics and battery systems, including all the Prii and Ford generations. Talk about differing engineering approaches....

Stay well,
Frank

 

[fbov]

Serial Hyper-miler here. ...

Welcome! You've got a very good idea how to drive a hybrid!!

The only thing I can offer is terrain mapping.

GPS Visualizer profile input form

www.gpsvisualizer.com

In Google Maps, select a route. In the Menu pull-down, look for "Share or Embed Link." Copy the link.

Open GPSVis, above. Paste the link under "Or provide the URL of data on the web." I also needed some permissions, but you get this.

This is (almost) a round trip. The first leg is 2-lane, the second leg is mostly highway. The car reported 49.3 mpg for the first leg, 50.5 for the second, but it's downhill, and I was cheating. I can't do that on flat ground.

Stay well,
Frank

 

[fbov]

Good observation. Anything that prevents the ICE from running will improve mileage. I try to park with climate off so the engine stays off when I start. Below 32F, climate state doesn't seem to matter, engine's on right away. We'll see if 0F brings ICE-only operation. (Li-ion batteries can't charge below 32F, or discharge below 0F.) Maybe next week?

 

[fbov]

...the type of guy I want building my hybrid ...

... is an engineer.

I don’t think a conscientious human in the loop can improve efficiency significantly. There are too many variables to juggle like temperature, road conditions, head winds, tail winds, tires, and such things that I don’t know anything about. The driver can only steer, accelerate and brake. ...

Good points, but I was able to learn. This data is all from a daily commute over the same rural 2-lane path.

• Baseline is the 2nd-5th month of ownership, Fall 2013. I gave myself 30 days to learn, then started measuring.
• Snow14 was the following Winter running Michelin X-Ice3 snows.
• Sum_14_ADSk is the following Summer, with some under-car aero mods installed. Unlike Paul's car, my aero mods didn't help and didn't stay on. What changed was my driving style.

What did I learn? To accelerate more slowly, so I charged the HVB at a higher rate, for a longer period of time. Makes beautiful music in the Escape, too.

I bought the escape because I prefer the Ford system design.

Me, too.

 

[fbov]

There is no algorithm to address a few too many pounds of the car and the driver. Reduce the weight and gain more mpgs.

Not necessarily, anymore. This is very true of conventional drivetrains, before regenerative braking.

Once you add an energy recovery system, mass effect drops by the efficiency of the recovery system. As I recall, the C-Max was ~80% efficient (AC generate, invert, DC charge, DC discharge, invert, AC drive). In the data I posted above, I'm getting 5.5% regen return with a 95%+ regen score. (Ask me what that did to my conventional brakes.)

Plus, weight only matters to rolling resistance (no aerodynamic or combustion effects) and RR losses are insensitive to speed and load. Its great impact is on acceleration, and recovery on deceleration mitigates a large fraction of the kinematic loss. Hybrids are different.

 

[fbov]

The reason you get better mpgs then Prius is purely your driving style, ...

That's a false statement.

1) Prius vehicle is smaller. Drag force is1/2 x Cd x Speed^2 x rho (mass density) x CA (cross-sectional area, HxW)

• 2014 Prius height x width = 58.7 x 68.7 = 4033 sq. in.
• C-Max height x width = 63.9 x 72 = 4601 sq. in. (14%> Prius)
• Escape height x width = 68.6 x 74 = 5076 sq. in. (26%> Prius)

2) Prius Cd (drag coefficient) is lower. It historically falls with each generation through the 0.3-0.24 range. C-Max was touted as 0.30 Cd while I've not seen anything for the new Escape, so I'd estimate it at 0.35 Cd. That's another 25% and 45% advantage to a moving Prius

3) Prius engine is smaller, and a true hybrid in that early generations had small motors and could not accelerate by EV.
Great teardown videos of all Prius and Ford hybrid drivetrains here, including some recent Honda units. HF45 may be next?

https://www.youtube.com/user/WeberAuto

The small motors in early Prii along with the small ICE point to a "helper" design strategy: take a very efficient gas engine and improve its efficiency with motor/generators. First Gen Prii were slow, and that's always been efficient. The most powerful makes 134 HP and it's still 10 sec. 0-60.

4) Even Consumer Reports gets good mileage.
But they also note "Lackluster acceleration" and "Feels insubstantial for the price" as lows in the 2020.

I'll stick with the Escape!

 

[fbov]

... Simple physics....

That's fake news for sure

I'm one two posts behind your misconceptions. My last post has more-complete physics in it. Do you realize you've marked yourself?

And I see you're on a roll!

Let's put this to bed.
Gen3 Prius got 44 MPG (EPA 48 MPG) in CR testing, weighed 3115 lb.
Gen4 Prius got 52 mpg (EPA 52 mpg) in CR testing, weighed 3080 lb.

WOW 25% for only 25 lb.!! If that were the case, passengers would matter!!

In fact, most of Toyota's improvement comes from the same place as Ford's... better ICE management. Gen4 is an updated 1.8L 2ZR-FXE. As you know, Ford upped displacement 200 cc from HF35 to HF45. This is where smart engineers look, at "low hanging fruit." ICE is >40% efficient. More than 150% of the energy is wasted.

(PS. Your RAV4-Highlander example is missing the drivetrain and vehicle size factors that drive this kind of thing.)

 

[fbov]

...weight is still a big factor for efficiency.

I pulled this efficiency data for normally aspirated engines from the attached SAE report .

Highlighted areas are 34% Brake Thermal Efficiency. Not only are new engines more efficient, they have larger operating ranges that exceed historical best of a decade earlier, with large, low-torque operating range. I also attached a report on a 2018 Toyota Camry engine that gives you details behind the prototype above.

I expect Ford has similar efficiency maps for the 2.5L in the Escape Hybrid. It's why I'm getting better mileage than I did in the smaller, lighter C-Max.

 

[fbov]

I routinely bring in 150-300 lb. loads, doubling the load on one leg of a round trip. Any weight effect is swamped by speed, terrain and weather differences.

C-Max reported trip regen "savings." I saw no more than a 9% effect on routes with a lot of stops.

 

[fbov]

Of course there are other variables since engines are bit more powerful in Sienna/Highlander, but still the point is still valid here that less weight gives us better mpgs.

Post 51... is that where you claimed that a more powerful engine got worse mileage because its car's heavier? More powerful engines have been less efficient since long before my time. Why do you keep proving my point?

Your point is well taken, but rendered moot, in this case, by regenerative braking.